extract_subtitles.txt

#!/bin/bash

# This script is a modified version of neik's script at https://emby.media/community/index.php?/topic/83855-script-to-extract-subs/&do=findComment&comment=878783, cleaned up for my usage.
DEBUG=false
DOCKER=true

lang_list=(eng)
DIR="/mnt/user/Anime"
mkvinfocmd=(docker exec MKVToolNix /usr/bin/mkvinfo)
mkvmergecmd=(docker exec MKVToolNix /usr/bin/mkvmerge)
mkvextractcmd=(docker exec MKVToolNix /usr/bin/mkvextract)

jsonoutput() {
    "${mkvmergecmd[@]}" -J "$1" | jq -r '.tracks |map((.id | tostring) + "," + .type + "," + .properties.language + "," + (.properties.forced_track|tostring) + "," + .properties.track_name + "," + .properties.codec_id + "," + .properties.encoding) |join("\n")'
}

info_log() {
    printf "Log: %s \n" "$1"
}

debug_log() {
    if [ $DEBUG = "true" ]; then
        printf "Debug: %S \n" "$1"
    fi
}

movefile() {
    if [ ! -f "$2" ]; then
        mv "$1" "$2" #>/dev/null 2>&1
    fi
}

echo "Working from directory $DIR"

while IFS= read -r -d '' MKVFILE; do
    MKV=${MKVFILE/\/mnt\/user//\/storage/}
    BASENAME=$(basename "$MKV" ".mkv")
    DIRNAME=$(dirname "${MKV}")
    OUTPUTDIR=$(dirname "${MKVFILE}")
    NEWBASEFILE=${BASENAME// /_}
    NEWNAME="${NEWBASEFILE}.***"

    if [ "$DEBUG" = "true" ]; then
        debug_log "MKVFILE: $MKV"
        debug_log "BASENAME: ${BASENAME}"
        debug_log "DIRNAME: $DIRNAME"
        debug_log "NEWBASEFILE: $NEWBASEFILE"
        debug_log "NEWNAME: $NEWNAME"
        "${mkvinfocmd[@]}" -r "$DIRNAME/$BASENAME.log" "$MKVFILE"
    fi
    subtitlename=${BASENAME%.*}
    # Test if an english subtitle exist
    info_log "No subtitles found for $BASENAME"
    # Number of matching embedded subtitle tracks
    subnum=$(jsonoutput "$MKV" | grep -c subtitles)
    info_log "Number of matching subtitles is $subnum"
    for lang in "${lang_list[@]}"; do
        # Find out which tracks contain the subtitles
        info_log "Checking $BASENAME for $lang subtitle tracks"
        jsonoutput "$MKV" | grep subtitles | grep "$lang" | while read -r subline; do
            # Grep the number of the subtitle track
            tracknumber=$(echo "$subline" | cut -d "," -f1)

            # Grep the subtitle format
            format=$(echo "$subline" | cut -d "," -f6)
            forced=$(echo "$subline" | cut -d "," -f4)
            language=$(echo "$subline" | cut -d "," -f3)
            track_name=$(echo "$subline" | cut -d "," -f5)

            debug_log "Subline: $subline"
            debug_log "format: ${format}"
            debug_log "forced: $forced"
            debug_log "language: $language"
            debug_log "track_name: $track_name"

            case $format in
            S_TEXT/UTF8)
                format=".srt"
                ;;
            S_TEXT/SSA)
                format=".ssa"
                ;;
            S_TEXT/ASS)
                format=".ass"
                ;;
            S_TEXT/USF)
                format=".usf"
                ;;
            S_VOBSUB)
                format=""
                ;;
            S_HDMV/PGS)
                format=".sup"
                ;;
            *) ;;
            esac

            # Get base name for subtitle
            subtitlename=${BASENAME%.*}

            # Extract the track to a .tmp file
            info_log "Extracting subtitle track to temporary file for $BASENAME"
            "${mkvextractcmd[@]}" tracks "$MKV" "${tracknumber}:${subtitlename}${format}.tmp" >/dev/null 2>&1
            if [ $DOCKER = "true" ]; then
                docker cp MKVToolNix:/tmp/"${subtitlename}${format}.tmp" "${subtitlename}${format}.tmp"
                docker exec MKVToolNix rm -rf "/tmp/${subtitlename}${format}.tmp"
            fi
            if [ -f "${subtitlename}${format}.tmp" ]; then
                chmod g+rw "$subtitlename$format.tmp"
            fi
            if [ -f "${subtitlename}${format}.tmp" ]; then
                debug_log "File exist: $subtitlename$format.tmp"

                if [ -n "$track_name" ]; then
                    subname="${track_name//[^A-Za-z0-9._-]/_}"
                else
                    subname="$language"
                fi
                if [ "$forced" = "true" ]; then
                    # rename forced subtitle for plex
                    info_log "Subtitle track appears to be forced, renaming as ${subname}.forced$format"
                    if [ ! -f "$OUTPUTDIR/$subtitlename.${subname}.forced$format" ]; then
                         movefile "${subtitlename}${format}.tmp" "$OUTPUTDIR/${subtitlename}.${subname}.forced$format"
                    else
                        rm -rf "${subtitlename}${format}.tmp"
                    fi
                else
                    # Rename in .$lang_en.$format for plex
                    info_log "Subtitle track appears to be full, renaming as ${subname}${format}"
                    if [  ! -f "$OUTPUTDIR/$subtitlename.${subname}${format}" ]; then
                        movefile "${subtitlename}${format}.tmp" "$OUTPUTDIR/${subtitlename}.${subname}${format}"
                    else
                        rm -rf "${subtitlename}${format}.tmp"
                    fi
                fi
            fi
        done
    done
done < <(find "$DIR" -size +180M -name '*.mkv' -print0 | sort -n)